misc: is_different_array handles undefined arrays as being equal and map_without_undefined should check if map is defined first
misc: is_different_array handles undefined arrays as being equal and map_without_undefined should check if map is defined first

tscholl2/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc